‘Oblivion’ star Tom Cruise gave Jimmy Kimmel a summary of his Irish ancestry on Thursday night as he gushed about his brief trip to his ancestral home last week.

The action star was presented with a certificate of Irish heritage by the country's Minister for Foreign Affairs and Trade Eamon Gilmore earlier this month and learnt his relatives can be traced back to the 9th century after two female fans researched his family lineage as a gift.

Speaking on 'Jimmy Kimmel Live!' on Thursday, the 50-year-old Hollywood star said: "I had no idea it went back that far."

The Irish American revealed his ancestors once owned a town called Hollywood in County Wicklow and one of his elders was known as a "famine hero" when they returned to Ireland from New York to save people from being evicted from their homes. They also had a lot of control over the capital city of Ireland.

“You couldn't make this stuff up - I found out my ancestors owned a town called Hollywood. It's wild. One guy was a famine hero,” Cruise told Jimmy Kimmel.

He explained his lineage, "He was in New York and this guy who was helping to run estates wanted to throw tenants off the farm, so he got on a boat in the middle of winter, went all the way back and reinstated the tenants on the farm. He fired the lawyer and they threw him a big dinner in celebration.

"There were knights for Strongbow in the 12th century. They said we could be there for a long time, but I only had 40 minutes. They showed me a picture where the foundation of the castle was - they said my family owned most of Dublin at a certain point. It was unbelieveable."

During his trip to Ireland Tom found it "incredible" to find out more about his ancestors and embraced his Irish side by undertaking a master class in pint pouring at the world famous Guinness Storehouse in the capital.

Speaking at the time, he said: "To learn about the history of my family - it was incredible.”

"I'm very proud to be Irish. There's a pride in America of being Irish. I can't wait to come back and I want to visit the land of my ancestors and the castle that they had."